1. Field of the Invention
This invention relates to biopsy needles, and more specifically to concentric biopsy needles adapted for counter-rotating movement for cutting through soft tissue and sawing through bone to obtain the desired sample.
2. Prior Art
A variety of needles is available to obtain samples of soft tissue. One standard class includes a closed tip needle with a side slot or opening near the tip. Soft tissue is sucked into the slot by means of applied vacuum. A cutter is used to separate the material which has been sucked in from the surrounding tissue. This type of needle is used predominantly for biopsy of the synovial lining of joints, but may also be used for liver, spleen, kidney and other soft tissues or organs.
A needle disclosed in Perez et al, U.S. Pat. No. 2,541,542 utilizes a loop of thread, extending from a cannula which has been advanced to a desired position with the aid of a style, to cut a section of tissue. The thread is tensioned to cut the tissue and to hold the same during withdrawal of the needle.
Baylis et al provide an elongated inner needle for initial penetration of body tissue in U.S. Pat. No. 4,177,797. An outer hollow cylindrical cutting tube is slidably received over the needle member until it also penetrates the body tissue. Both the tube and needle are then simultaneously withdrawn with the sample collected interiorly of the tube.
Banko U.S. Pat. No. 3,732,858 teaches the possible use of an electric motor for revolution of inner and outer jaws relative to one another, from an open to a closed position, as disclosed at columns 7 and 11 therein, for example. Relative rotation of a drill-like structure in conjunction with suction means is used to contain and progressively remove portions of a cutting.
Hallac U.S. Pat. No. 3,605,721 discloses a fixedly connected (soldered) coaxial inner and outer combination of needles 16 and 12 in conjunction with trochar 20. Needle 16 is telescopically received within needle 12. Both needles are provided with generally V-shaped coincident prongs. The connection between the needles collapses upon relative motion therebetween, thus capturing the biopsy specimen.
Jamshidi U.S. Pat. No. 3,628,524 provides a double sawtooth cutting edge in a biopsy needle for cutting soft tissue, such as liver, kidney, spleen, skin, muscle, etc., while a rasplike exterior surface is used for bone specimens. The needle is described as providing specimens without damage through crushing.
A variety of sawtooth ended cannulas, with or without outer sleeves or inner trochars, have been devised to obtain bone samples and samples of the intervertebral disc. Ackermann U.S. Pat. No. 2,919,692, for example, manually rotates a trephine 9, having six very fine sharp teeth undercut on their leading edges, for sawing purposes in a vertebral biopsy, within a guide 3.
Hofsess U.S. Pat. No. 3,893,445 is a further disclosure of a trephine cannula with multiple sawtooth design.
Another soft tissue device, disclosed in Steward U.S. Pat. No. 3,175,554, includes a first needle which is introduced to the area of interest along with a fitted stylet. A hollow bifurcated inner needle is inserted through and beyond the first needle. Camming action causes the needle to spread and to capture a sample of soft tissue. Withdrawl of the bifurcated needle leads, by camming action, to contraction of the portions thereof to contact each other, thus severing and trapping the biopsy within the split needle.
Hevesy U.S. Pat. No. 3,949,747 teaches the use of interchangeable ends in a biopsy set.
Other U.S. patents known to relate to biopsy devices include Cromer et al U.S. Pat. No. 2,710,000; Eskridge et al U.S. Pat. No. 3,683,891; Jamshidi U.S. Pat. No. 3,800,783 and Lacey U.S. Pat. No. 3,913,566.
A United Kingdom patent application (GB No. 2,022,421) discloses the use of a punch assembly 3, axially extensible from a shaft 1 having a prong-shaped cutting edge 1a. The apparatus requires successive punching operations to extract a sample.
However, none of the suction-type devices can penetrate cortical bone dependably. None preserve the natural architecture or orientation of tissue or cell types within the specimen. Since an accurate diagnosis frequently depends on an appreciation for the geometric relationships of one or more tissue types to others, it may occur that, even in soft tissue, no diagnosis can be made.
The forked needle type of needle also cannot biopsy bone and tends to mutilate the architecture of the specimen.
All of the sawtooth tip bone biopsy needles macerate and destroy much of the organization and architecture of the soft tissue and often the tumor system being examined. In essence, these devices saw a core of bone, cortical and/or trabecular, but work poorly with soft tissues. All presently used sawtooth ended trephines and needles grossly macerate the soft tissue or tumor tissue, thus destroying the organization and architecture, the relations of one tissue type to another, and make diagnosis of many tumors or pathologic conditions difficult or impossible.
The thin, small soft tissue needles, whether suction or mechanical in action, are not strong enough or appropriate for bone biopsy. Any attempt to use such needles in this way may subject them to a great risk of breakage within the patient. All such soft tissue needles compress, harm, and macerate the tissue to some extent, such that diagnosis dependent upon tissue architecture may be impossible to be made reliably.
Simple needles, while useful in the diagnosis of infection, rarely obtain enough tissue for tumor diagnosis. Such simple needles are typically useful only for aspiration of cavities where a diagnosis can be made from a smear of diseased cells.